This invention relates to filling apparatus, and more particularly to such apparatus for filling large, open-mouth containers, such as bags, rigid drums or the like with a fluent or pourable material (e.g., a dry powder, particulate material, or a liquid), for collecting dust or vapor from within the container during filling, and for preventing splashing of the material during filling.
In filling large containers, such as shown in U.S. Pat. No. 3,777,775, with bulk quantities of powdered chemicals or other materials, it is often necessary to collect dust formed during the filling operation within the container in order to protect personnel and the environment. Heretofore, in filling large flexible bags, one known dust collection system was used in which workmen pulled the bag erect up over a form and secured a rigid hood to the form. The powdered material was delivered into the bag via a fill-tube through the hood. An opening in the hood was connected to a suction-type dust collector which drew the dust from within the container and collected it. This system, however, required several workmen to secure the bag and the hood to the form. In filling some bags, it is sometimes desirable to weigh the material delivered to the bag by supporting the bag on a scale and weighing the bag as it is filled. This prior art dust collection system, however, often interfered with weighing the product delivered to the bag during the filling operation. Also, the rigid hood could not be readily adjusted to accommodate bags of different cross-section.
In filling bags or other containers with powdered material containing substantial quantities of entrained or adsorbed gases including air, such as barite used for oil-well drilling mud or the like, it is often desirable to de-aerate the powder once it is in the container thereby to reduce the volume of the material and to prevent sloshing or shifting of the powder in the container.
In U.S. Pat. Nos. Re. 23,504, 2,531,743, 2,815,621 and 2,954,203, various apparatus are disclosed for vacuum filling a container with powdered material.